To explain what I mean I will take this parallel of the technique of music, of which I know even less than of the technique of natural history. To begin with a simple though moving musical instrument, suppose an expert told me that a coach-horn could be blown quite as well if it were only two feet long. I should believe him; partly because it seems probable enough, and partly because I know nothing about the matter. I am not even an incompetent coach-horn blower. But I should certainly not believe him if he told me, as a generalization about all musical instruments, that half a musical instrument was better than no music, or even as good as any music. I should disbelieve it because it is inconsistent with the general nature of a musical instrument, or any instrument. I should disbelieve it long before I had thought of the thousand particular instruments to which it does not apply. I should not primarily need to think of the particular examples, though they are obvious enough. A stringed instrument cannot even be called stringed without two fixed points to hold both ends of the string. At the stage when the fiddle-strings floated like filaments in the void, feeling their way towards an evolutionary other end of nowhere, there could be nothing serving any purpose of a fiddle. A drum with a hole in is not a drum at all. But an evolutionary drum has to turn slowly into a drum, when it has begun by being only a hole. I cannot see any survival for a bagpipe that begins by being slit; I think such bagpipes would die with all their music in them. I feel a faint doubt, mingled with fascination, about the idea that a violin could grow out of the ground like a tree; it would at least make a charming fairy story. But whether or no a fiddle could grow like a tree, I feel sure nobody could play on it while it was still only a twig. But all these, as I say, are only examples that throng into the mind afterwards, of a principle seen in a flash from the first. Of things serving particular purposes, by a balance and arrangement of parts, it _cannot_ be generally true that they are fit for use before they are finished for use. It is against the general nature of such things; and can only be true by an individual coincidence. I can see for myself, for instance, that some particular case like the trunk of an elephant might really be compared to the simpler case of the coach-horn. Length and flexibility _are_ mere matters of degree; and I might possibly find it convenient if my nose were six inches longer, and sufficiently lively to be able to point right and left at various objects on the tea-table. But this is simply an accident of the particular qualities of length and laxity, not a general truth about the qualities of growth and use. It is not in the least true that I should experience the least convenience from the membrane between my fingers thickening or widening a little; even if an evolutionist at my elbow comforted and inspired me with the far-off